There are manifold areas in the food industry wherein stabilized mixtures and emulsions of oil and water rich phases are produced and utilized. Specific products are mayonnaises, dressings, dips, and spreads of the margarine, edible oil/fat and butter based types. Many fat rich sauces also possess emulsion characteristics.
For many of these products, emulsification and emulsion stability is achieved using well-known emulsifiers which are of surfactants. Among the most utilized are lecithin and a number of mono- and di-glycerides. Mono glycerides are particularly useful for the production of low fat, high water spreads. GB 574,389 is one of the original patents in this field.
There is a growing interest and consumer demand for healthier products with reduced fat contents, particularly in the range of products mentioned above. There are acknowledged methods for the preparation of reduced fat foodstuffs comprising emulsions and a number of patented methodologies exist. Examples are: EP 0 420 315, EP 0 422 712, U.S. Pat. No. 4,849,243 which focus on reduced- and low-fat spreads.
Much recent interest has focused on the incorporation of soluble fiber type polysaccharides and oligosaccharides such as inulin to improve water-binding, lower overall fat within, and thicken the aqueous component of, emulsified products such as dressings and spreads. A process for low-fat emulsified dressings containing inulin is described in EP 0 792 587. However, egg yolk which is rich in lecithin is used as the emulsifier, and high shear emulsification is used to produce the final dressing. Soluble fibers such as inulin are also acknowledged pre-biotic materials and are considered to promote good gut-health in humans, and their incorporation in foodstuffs is therefore also interesting from a health standpoint. However, as mentioned above, it is necessary in many such products to add one of the standard emulsifiers, or indeed to incorporate at least a chemically modified starch, which performs a similar function and is no longer a natural product.
Starch is also widely used as a fat-replacement in products such as low-fat mayonnaises, and in spreads, for example U.S. Pat. No. 4,591,507, however the addition of a standard emulsifier is almost always necessary unless the starch is chemically modified (JP 2000-236810). It is therefore recognized that it would be beneficial to utilize a natural product that can emulsify, stabilize products such as dressings, mayonnaises and spreads, particularly if a beneficial soluble fiber component can be incorporated into the final product, and especially if reduced fat and low fat food products can be produced in a simple, reliable manner. To date, however, this has proved difficult and very few natural ingredients and processes allow the easy manufacture of such products.
EP-A-1 361 264 discloses a fat or oil compositions containing gramineous β-glucans, which are produced at an elevated temperature using preferably β-glucans having a lower molecular weight, i.e., a molecular weight below 500,000, often below 200,000, more often below 100,000 Dalton. Emulsions made from such β-glucans have to be violently agitated using high-shear mixing apparatuses in order to obtain a stable emulsion. Using non-high shear mixing will lead to a phase separation of the emulsion.
The present invention addresses many of these issues. We have discovered a natural emulsifying agent which produces stable emulsions of edible oils, fats and other non-water-miscible liquids in water. Moreover, the emulsion is produced without resource to high energy or high shear mixing using this emulsifier. This emulsifying agent can be used to produce emulsions to be used in foodstuffs such as reduced fat mayonnaises, dressings, dips, full-fat and reduced fat spreads, sauces and also for the production of emulsified cosmetic products for atopic application. In this invention, materials obtained from oat or barley grains which are rich in healthy (1-3),(1-4)-β-D-glucans are utilized in a specific way to enable the formation of stable emulsions and dispersions.